Air-cushion for printing-presses.



/NVENTo/e.

A TTORNE YJJ R. MIEHLE. AIR CUSHION POR PRINTING PRESSES.`

ABPL'IGATIOH FILED M1119, 1902. RENEWED SEPT. 2a, 1904.

Wim/5555s.-

i Y' IINIrn-D STATES PATENT a-oifrIon.

Renner/Minuta, or cIIIcAeo. IL'LI-"Noi's.y l

Ain-cusHioN Fon PRINTING-PRESSES.

Specification of Letters Patent.

Patented Noir. 2o, 1906.

ippiiminieaneemberIe,1902. Ranma-september 26,1904. seating. 225.976. y'

, To a/ZZ whom it may concern:

' and a strain upon the driving mechanism Be it. known that 1, ROBERTMIEnLE, a

citizen of the United States, residing in Chiin the county of Cook andState of Illinois, have invented a new and, useful Improvement inAir-Cushions for Printing- Presses, of which the following isaspeciiication. i l

cago,

, In that classici1` printing-presses in which a i reciprocating bed ismoved to and fro beneath an impression-cylinder it has been customarysometimes to provide a dash-pot or air-cushion cylinder at each end ofthe machine to receive dash-pistons mounted on the reciprocating bed forthe purpose of cushioning the end of the stroke toobviate the shock andstrain upon the mechanism due to the stoppage and reversal. A commondiiiculty with these device; is the liability to too great compressionof the air at the end of the stroke after the momentum of the bed hasbeen checked, resulting in the waste of power `out shock.

The object of the present invention is to' produce the above-outlinedconditions as nearly as possible, andwith this end in view I provide thecylinder or dash-pot near its.

closed end with an outlet provided with a valve connected to andoperatedby the constantly-moving parts of the press by mechanism so contrivedand timed that as the pistonl 'nears the bottom of the Vcylinder thisvalve will be opened to permit the escape of air from the cylinder andprevent acontinuing compression of the air in the cylinder, and the airwhich thus escapes from the cylinder is conveyed to an auxiliary closedair-tank, from which it flows out again into the cylinder on the returnstroke of the piston. A single auxiliary air-tank may be employed fortheA two air-cylinders at each end of the stroke, together with a singlevalve and a single cam or operating mechanismfor,controlling the valveas the air-cylindersoperate alternately, or a single cylinder cushioningboth ends ot' the stroke and a single fair-,tank and valve may be used.Y

The construction and arrangement of this device will be betterunderstood fromy the yfollowing description and the accompanyingdrawingshwhich form a part of thisspecification, and in which-` Figure 1is an end view, partly in section, of a printing-press containing theinvention;

and Fig. 2 is a side view, partly in section,of

the same.

In said drawings, 10 is the reciprocating bed of the press. y y f 11 and12 are the two pistons connected to said press-bed. p 13 and 14 are thetwo dash-pots or air-cylinders into the open mouths of'which alternatelythe pistons 11 and 12 ,enter in-the toand-fro movement of the press-bed.

15 and 16 are two pipes opening from the interior, respectively, yof theVcylinders 13-,and

14 and proceeding to thelcommoyn three-way valve 17, located at thejunction` ot the two pipes 15 and 16.

18 is a third pipe proceeding from thelvalve v17 to the auxiliary tank19..k To the handlev 20 of the valve 17 is connected one end of abell-crank lever 21, the other end, of which is provided with a roller22, .engaging the groove of the cam 23. This cam 23 is mounted on ashaft 24, which is connected to the continuously-moving portions of thepress mechanism, (the connection not lboeing shown in the drawings,)andits revolution isso timed with reference to the movement ofthe press`that when the piston 11 has entered the cyl-I ind er 13 the valve 17will be closed and remain closed until said piston has neared the bottomof the cylinder 13 and the termination l of the upstrokein thatdirectionapproached. At this point the revolutionof the cam 23 will cause thevalve .17 to be opened to permit the iiow of thel air from the c. inder13 to the tank 19, in which position the valve will. close the IOOentrance to the pipe 16, and the cam is Jfurtherr contrived that thiscondition will be maintained until after the'piston 11 is started on its'return stroke and untilthe piston 12 has entered' the cylinder 14 andapproached in like manner the termination of its stroke,

whenthe cam in its further revolution willy close the valve 17 againstthe cylinder l13 and `open it as to the cylinder 14. The result ofthe-auxiliary air-tank, which lauxiliary this arrangement is that themotion ofthe l as the piston of the air-cylinder nears the press-bed ischecked in either direction by compression of 'air in one or other ofsaid aircylinders up to a certain point in the stroke, and thereafter arelief of the. compression takes .place to the extent of the capacity ofantank is emptied or its contents reduced to atmospheric pressure ateach alternate stroke.

The result is that the vair-cushion operates noiselessly and smoothly tocheck the momentum of the press-bed steadily and Without puttinganyextra strain upon the driving mechanism of the press, thus greatlyim` proving the movement, diminishing the Wear andstrain, and lesseningthe power required to drive the press.

Some ofthe benefits of this invention will be -attained by permittingthe valve 17 to deliverthe escaped air into the open atmosphere, .and asair escapes very quickly itis extremely difficult to automatically openand vent in such timing and in such manner as to prevent the residue ofmomentum from causing too violent a shock at the reversal of thebedmovement. With the auxiliary air-tank this di'liiculty is notexperienced, as the air does not escape into the open atmosphere, butinto the auxiliary air-tank when the valve is opened, and consequentlyall shock is prevented, because some pressure is still/ maintained uponthe piston at the time of rei versal.

the air at the end ofthe stroke, substantially as specified. t y 2. Thecombination With the. reciprocating press-bed of a cushioningair-cylinder, a piston for said cylinder, an auxiliary air-tanklcommunicating With the cylinder by a valve'- controlled passage, andmeans for automatieally l)pening and closing said valve of said passage,such opening taking place before reversal of the bed, substantially asspecified.

3. The cushioning air-cylinder Wherewith is combined an auxiliaryair-tank, an outlet from the cylinder-to said tank, a valve controllingsaid outlet, and means for opening said valve automatically as thepiston ofthe air-cylinder nearsthe closed end ofthe cylinder. v i

4. The combination with a reciprocating device Whose stroke is tobecushioned, of a cushioning air-cylinder having an auxiliary air-tank, anoutlet from the cylinder ,to said tank, a valve controlling said outlet,and Vmeans for opening said valve automatically closed end ofthecylinder.

' 5. The combination with a reciprocating, press-bed, of thecushioningVair-cylinder, one at each endthereof, the pistons one foreach by ka valve, and means for automatically opening said valvesalternately as the pistons of the air-cylinders near the closed ends'ofthe cylinders whereby the compression ofthe cylinder, an outlet'fromeach cylinder closed ically controlling the outlet Vair from thecylinders into the auxiliary tank alternately from the two cylinders bythe movement of .the

press, substantially as specified.

7. The combination with a cushioninU-cylinder of an auxiliar chamberinto Whieh the cylinderl vents, andy an automatic valve 4controlling theventing and timed to permit it when the pressure reaches a predetermineddegree, substantially as specified. f '8. The combination With-acushioning-cylinder of a closedauxiliary chamber into Which-the cylindervents, a valve controlling the venting andtimed to permit itwhen thepressure in the cylinderreaches a predetermined degree, and means for oening said galve automatically, substantial y as specied. 9. Incombination With a spring for coun- -teracting orreducing the momentumof the reciprocating bed' of a rinting-press,` means. timed to thetravel of t e bed for first retaining the resistance of the springduring'a certain portion offsa'id travel and for afterward from apredetermined point in said ltravel so controlling said resistance as torestrict the further increase thereof duringv a further travel. f

10. I n combination with a spring for counteracting or reducing themomentum of the reciprocating bed of a rinting-press, means IOC IIO

timed to the travel of t e bed orirst retaining the resistance of thespring to counteract or overcome the momentum acquired by the bed duringa portion of said travel, and for afterv'vard, While reducing such'resistance during a further travel beyond a predetermined point,retaining sufiicient resistance at the end of the travel to assist instarting the bed in the reverse direction.

1 1. In combination With a spring for coun- .teracting or reducing themomentum of the reciprocating b'edof a printing-press, ymeans for firstretaining the resistance of the spring to counteract or reduce themomentum acquiredby the bed in its travel, and cam-actuated mechanismderiving motion froml the press for afterward. so controlling suchresistance as to -restrict the furtherincre'ase thereof during thefurther travel.

12. The combination with the cylinder and piston of an air-spring for a'reciprocating printing-press bed, of an outlet-valve and mechanismtimedto the travel of the bed for opening saidvvalve at a predetermined pointin said travel for releasing air Jfrom said' cylinder to revent afurther increase of compression uring the further travel.

13. The' combination with the cylinder and piston of an air-spring for areciprocatingv printing-press bed, of an outlet-valve an mechanism timedto the travel of the bed for keeping said valve closed to retain the airin the cylinder to a predetermined point in said travel and afterwardopening said valve to restrict the further compression of the air in thecylinder during the further travel. l

14. The combination with the cylinder and piston of`an air-spring for areciprocating printing-press bed, of an outletvalve and cam-actuatedmechanism timed to the travel of the bed for keeping the valve closedduring an earlier stage of the entering movement of the piston into thecylinder and afterward opening said valve at a predetermined point inthe travel of the bed and thereby providing for -the escape Aof air fromsaid cylinder during a further portion of said travel.

15. The combination with the cylinder and piston of an air-spring for areciprocatin printing-press bed, of an outlet-valve an cam-actuatedmechanism timed to the tra vel ofthe bed for irst keeping the valveclosed during an earlier stage of theentering movement of the pistoninto the cylinder, then opening said val ve at a predetermined point andafterward closing it before the next stroke of the b ed.

16. The combination with a printingpress bed and mechanism for givingsaid bed a reciprocating movement retarded at a certain stage of itsprogress, of a spring for counteracting the momentum of the bed andmeans for 'restricting the resistance of said spring from and beyondthat point in' said movement at or near which the retardation takesplace.

17. The combination with a printingpress bed and mechanism for givingsaid bed a reciprocating movement retarded at a certain stage of itsprogress, of an air-spring comprising a cylinder and piston forcounteracting the momentum-of the bed, an outcomprising a cylin er andpiston for counteri acting the momentum of the bed, an outletvalve tosaidcylinder and mechanismderi ving motion from the press for o eningsaid valve at or near that point in sai movement 'in either direction atwhich the retardation l,commences and closing it betore the next strokeof the bed.

19. In an air-cushion de vice of the character described, thecombination with the piston, piston-chamber having a vent-opemng, andthe auxiliary chamber into which said vent opens, ofmeans controllingthe movement of the air through said opening adapted to bring about themaximum resistance be-l fore the piston reaches the end of thecompressing stroke and thereafter to maintain a decreased resistance asthe piston moves to the end of its compressing stroke.

' 20. In an air-cushion device of the character described, thecombination with the piston, piston-chamber having a vent-opening, andthe auxiliary chamber into which said vent opens, of means controllingthe 'move-" ment of the air through said opening adapted to bring aboutthe maximum resistance before the piston reaches the end of thecompressing stroke. l

. ROBERT'MIEHLE. Witnesses:

EDW. S. EvARTs, H. M. MUNDAY.

